This invention relates to devices and techniques for encapsulating cables. More particularly, this invention relates to devices and techniques for providing rigid encapsulation for cables.
In many cable applications, it is necessary to splice into the central metallic conductor strands in order to rearrange the connections, to provide a local connection, or to isolate a predetermined cable length for testing purposes. In telephone cables, for example, it is frequently necessary to splice into one or more of the pairs of multiple conductors contained within the cable for repair purposes. Splices are also required when the distance between the two points to be spanned is greater than the length of the longest available cable.
In splicing cables it is necessary to expose the metallic conductors covered by the sheath to provide the desired connections. In order to protect the exposed conductors against deterioration caused by moisture, gasses, or other contaminants, and to protect against electrical short circuiting, it is necessary to reseal the individual conductors with electrically insulative material, such as electrician's tape, insulative sleeves and the like. In severely hostile environments, or in applications where the cable will be permitted to remain undisturbed for long periods of time, these insulators are known to break down and deteriorates with the resulting failure of the cable. It is thus necessary to provide a protective enclosure to prevent this occurrence.
In some applications, it is also desirable to provide a specific environment for a pair of spliced cable ends. The environment may be gaseous, e.g. helium or air, liquid, e.g. oil or grease, or solid, e.g. hard or soft, curing compounds.
In still other applications, it may be necessary to re-enter the cable after aplicing in order to alter the electrical connections by adding or removing branch-out conductors or by rearranging the electrical connections within the cable itself.
Many devices and methods are known for providing enclosures for cables subjected to a hostile environment, e.g. excess moisture, pressure from the surrounding soil in subterranean cables and the like. Both rigid and flexible enclosures have been provided in the past for this purpose. Examples of the former are found in U.S. Pat. Nos. 3,836,694, 3,255,302 and 3,183,302; examples of the latter are U.S. Pat. Nos. 3,495,026, 3,836,702 and 3,781,461. Such protective enclosures share in common the purpose of providing a controlled enclosed environment for a small section of a cable and are typically employed to protect exposed connections, one or more temporary or permanent cables splices and similar interruptions to the continuity of the customarily provided protective cable sheath.
The varying requirements stated supra and other requirements in the past have been met by protective enclosures tailored to the particular requirements of a given application. Thus, at present many different types of protetive enclosures have been developed to meet specific needs. Efforts to date, however, to provide a single protective enclosure capable of meeting the frequently conflicting requirements of a wide variety of applications have not met with success.